UNIX for Dummies Questions & Answers

I would like to extract the sequences larger than 10 bases but shorter than 18 along with the identifier from a FASTA file that looks like this:

> Seq I
ACGACTAGACGATAGACGATAGA
> Seq 2
ACGATGACGTAGCAGT
> Seq 3
ACGATACGAT

I know I can extract the IDs alone with the following code

Code:

grep ">" inputfile > Outputfile

and the sequences that are longer than 10 bases with the following one:

Code:

grep "[[:alpha:]]\{10\}" inputfile > outputfile

However, the ID will be also lost since they are pretty short and the output file will also contain the reads that are longer than 18. Thus, I need to generate a file containing the sequence ID followed by the actaul sequence. Therefore, the only sequence that will be present in the outputfile would be sequence 2:

Any ideas?
Thanks!